The present invention refers to a casting apparatus, more particularly for casting metals under strongly reduced pressure or in a protective gas.
The casting of metals under strongly reduced pressure or vacuum serves to prevent gas inclusions in the cast material and between the cast material and the casting mold. It is also possible under vacuum or in a protective gas to melt air-sensitive materials and pour them in molds.
In known methods, a required quantity of the casting material and the casting mold are placed in a vacuum chamber and the casting is carried out. In an alternative embodiment for large-scale industrial applications, the mold is located in a second, separate vacuum chamber. For the casting, the mold is transferred through a sealable opening to the chamber in which the liquid casting material is held in a container which is suitable for the casting operation. The casting material is poured into the mold, and the mold is brought back to the second chamber.
In this case it is advantageous that the melting and the exchange of the casting mold can be effected independently from each other. Disadvantageous, however, are the complications involved in the transport of the casting molds, the connecting opening between the two chambers, which limits the size of the molds, as well as the pivoting mechanism of the container for the casting material which is necessary for the casting operation.